fix(document): fire pre validate hooks on 5 level deep single nested subdoc when modifying after save()

lib/document.js

@@ -1716,6 +1716,9 @@ Document.prototype.$__set = function(pathToMark, path, options, constructing, pa
         } else {
           obj._doc[parts[i]] = val;
         }
+        if (shouldModify) {
+          obj.markModified(parts[i]);
+        }
       } else {
         obj[parts[i]] = val;
       }
@@ -2698,6 +2701,7 @@ function _getPathsToValidate(doc, pathsToValidate, pathsToSkip) {
             !doc.isDirectModified(fullPathToSubdoc) &&
             !doc.$isDefault(fullPathToSubdoc)) {
         paths.add(fullPathToSubdoc);
+
         if (doc.$__.pathsToScopes == null) {
           doc.$__.pathsToScopes = {};
         }

lib/types/subdocument.js

@@ -113,7 +113,7 @@ Subdocument.prototype.$__fullPath = function(path) {
 
 /**
  * Given a path relative to this document, return the path relative
- * to the top-level document.
+ * to the parent document.
  * @param {String} p
  * @returns {String}
  * @method $__pathRelativeToParent

test/document.test.js

@@ -12627,6 +12627,41 @@ describe('document', function() {
     doc.set('branding.logo.attachment', { name: 'coolLogo' });
     await doc.save();
     assert.strictEqual(attachmentSchemaPreValidateCalls, 1);
+
+    instance.set('branding.logo.attachment', { name: 'coolOtherLogo' });
+    await instance.save();
+    assert.strictEqual(attachmentSchemaPreValidateCalls, 2);
+  });
+
+  it('fires pre validate hooks on 5 level deep single nested subdoc when modifying after save() (gh-14591)', async function() {
+    let preValidate = [];
+
+    const createSchema = (path, subSchema) => {
+      const schema = new Schema({ [path]: subSchema });
+      schema.pre('validate', function() {
+        preValidate.push(path);
+      });
+      return schema;
+    };
+
+    const e = createSchema('e', { type: String });
+    const d = createSchema('d', { type: e });
+    const c = createSchema('c', { type: d });
+    const b = createSchema('b', { type: c });
+    const a = createSchema('a', { type: b });
+    b.add({ otherProp: String });
+    const NestedModelHooksTestModel = db.model('Test', a);
+
+    const newData = { a: { b: { c: { d: { e: new Date().toString() } } } } };
+    newData.a.otherProp = 'test';
+    const doc = await new NestedModelHooksTestModel(newData).save();
+    preValidate = [];
+    doc.set({ 'a.b.c.d.e': 'updated nested value' });
+    await doc.save();
+    assert.deepStrictEqual(preValidate, ['a', 'b', 'c', 'd', 'e']);
+
+    const fromDb = await NestedModelHooksTestModel.findById(doc._id);
+    assert.strictEqual(fromDb.a.otherProp, 'test');
   });
 
   it('returns constructor if using $model() with no args (gh-13878)', async function() {